1. Field of the Invention
This invention relates to vacuum cleaners and in particular to means for controlling self-propelled upright vacuum cleaners.
2. Description of the Background Art
In one form of upright vacuum cleaner, the wheels carrying the air suction nozzle are driven so as to provide a self-propelled movement of the nozzle over the surface being cleaned under the control of the user. An excellent example of such a vacuum cleaner structure is disclosed in U.S. Pat. No. 3,938,216 of Joseph F. Schmitz et al., which patent is owned by the assignee hereof. As shown therein, the handle of the vacuum cleaner is movably mounted by a spring biasing structure which urges the handle to a central neutral position. The user effects selective forward and rearward movement of the vacuum cleaner by moving the handle longitudinally against the action of the spring biasing structure. The spring biasing structure is mounted in the handle.
Another improved form of drive motor control for an upright vacuum cleaner is disclosed in U.S. Pat. No 3,857,076 of Thomas E. Hetland, which patent is also owned by the assignee hereof. Hetland discloses a reversible vacuum cleaner motor drive which is controlled by longitudinal movement of a handle extending into the bag housing. A cam is selectively engageable with a pair of switches for controlling the operation of the drive motor. Spring biasing means are provided for biasing the handle to a central neutral position.